FACEBOOKFaculty of Geology and Exploration, University of Mining and Geology, 1700 Sofia, Bulgaria
Founded 1934 by Prof. Dr Stefan Bončev
A Geo-Sciences Journal of the Geological Institute “Strashimir Dimitrov”, Bulgarian Academy of Sciences
Official Journal of the Carpathian-Balkan Geological Association
VOLUME 53 (1)/April 2024
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Faculty of Geology and Exploration, University of Mining and Geology, 1700 Sofia, Bulgaria
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Faculty of Geology and Exploration, University of Mining and Geology, 1700 Sofia, Bulgaria
Faculty of Geology and Exploration, University of Mining and Geology, 1700 Sofia, Bulgaria
Faculty of Geology and Exploration, University of Mining and Geology, 1700 Sofia, Bulgaria
Earth and Man National Museum, 4 Cherni Vrah Blvd., 1421 Sofia, Bulgaria
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Faculty of Geology and Geography, Department of Mineralogy, Petrology and Economic Geology, Sofia University “St. Kliment Ohridski”, 15 Tsar Osvoboditel Blvd., 1504 Sofia, Bulgaria
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Geological Institute, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl. 24, 1113 Sofia, Bulgaria
Earth and Man National Museum, 4 Cherni Vrah Blvd., 1421 Sofia, Bulgaria
Faculty of Geology and Geography, Department of Mineralogy, Petrology and Economic Geology, Sofia University “St. Kliment Ohridski”, 15 Tsar Osvoboditel Blvd., 1504 Sofia, Bulgaria
Geological Institute, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl. 24, 1113 Sofia, Bulgaria
Department of Environmental Sciences, Basel University, 4056 Basel, Switzerland
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Faculty of Geology and Geography, St. Kliment Ohridski University, 1000 Sofia, Bulgaria
Department of Environmental Sciences, Basel University, 4056 Basel, Switzerland
Faculty of Geology and Geography, St. Kliment Ohridski University, 1000 Sofia, Bulgaria
Climate, Atmosphere and Water Research Institute, Bulgarian Academy of Sciences, 66 Tsarigradsko Shose Blvd, 1784 Sofia, Bulgaria
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Geological Institute, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl. 24, 1113 Sofia, Bulgaria
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Geological Institute, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl. 24, 1113 Sofia, Bulgaria
Climate, Atmosphere and Water Research Institute, Bulgarian Academy of Sciences, 66 Tsarigradsko Shose Blvd, 1784 Sofia, Bulgaria
Geological Institute, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl. 24, 1113 Sofia, Bulgaria
Geological Institute, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl. 24, 1113 Sofia, Bulgaria
National Museum of Natural History, Bulgarian Academy of Sciences, 1 Tsar Osvoboditel Blvd, 1000 Sofia, Bulgaria
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National Museum of Natural History, Bulgarian Academy of Sciences, 1 Tsar Osvoboditel Blvd, 1000 Sofia, Bulgaria
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Plovdiv University “Paisiy Hilendarski”, Faculty of Biology, Department of Ecology and Environmental Conservation, 24 Tsar Asen Str., 4000 Plovdiv, Bulgaria
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National Museum of Natural History, Bulgarian Academy of Sciences, 1 Tsar Osvoboditel Blvd, 1000 Sofia, Bulgaria
National Museum of Natural History, Bulgarian Academy of Sciences, 1 Tsar Osvoboditel Blvd, 1000 Sofia, Bulgaria
National Museum of Natural History, Bulgarian Academy of Sciences, 1 Tsar Osvoboditel Blvd, 1000 Sofia, Bulgaria
Plovdiv University “Paisiy Hilendarski”, Faculty of Biology, Department of Ecology and Environmental Conservation, 24 Tsar Asen Str., 4000 Plovdiv, Bulgaria
National Museum of Natural History, Bulgarian Academy of Sciences, 1 Tsar Osvoboditel Blvd, 1000 Sofia, Bulgaria
ARTICLES IN THIS ISSUE
Faculty of Geology and Exploration, University of Mining and Geology, 1700 Sofia, Bulgaria
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Faculty of Geology and Exploration, University of Mining and Geology, 1700 Sofia, Bulgaria
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Faculty of Geology and Exploration, University of Mining and Geology, 1700 Sofia, Bulgaria
Faculty of Geology and Exploration, University of Mining and Geology, 1700 Sofia, Bulgaria
Faculty of Geology and Exploration, University of Mining and Geology, 1700 Sofia, Bulgaria
Faculty of Geology and Exploration, University of Mining and Geology, 1700 Sofia, Bulgaria
Abstract:
The Lower Palaeozoic marine sediments in NE Bulgaria could be considered not only as a potential hydrocarbon source rock, but also as a potential unconventional oil and gas reservoir. Several wells have penetrated this succession composed of mudstones, shales, siltstones, minor limestones, and marls. The knowledge on the major parameters of these rocks is rather obscure and is based on scarce rock sample data, because only a limited interval was drilled by coring, while most of the section was covered only by logging. Therefore, the current study combines geological, geophysical, and geochemical methods to characterise and assess the hydrocarbon potential of this succession. In the studied samples, one of the main parameters – total organic carbon, varies between 0.5% and 2.61%, which defines the rocks as having fair to good potential. A relatively positive correlation is observed between total organic carbon content and geological depth. The Lower Devonian–Silurian sediments exhibit generally higher total organic carbon content than the other part of the section. The applied method of using well-loggings allows the identification of vertical and lateral distribution of organic matter. A good correlation was observed between the total organic carbon data yielded by the geochemical method and the different well-log calculations. The obtained data on the type of organic matter and the degree of maturity show mainly gas potential of the shale succession. Different approaches, using Rock-Eval analysis and classical methodology of vitrinite reflectance (Ro), were applied for thermal maturity evaluation. Such combination and integration of different methods provide a more detailed and wide-ranging assessment of the Lower Palaeozoic sediments, and the data received could change the prospect and exploration strategy of a potential unconventional hydrocarbon resource.
Earth and Man National Museum, 4 Cherni Vrah Blvd., 1421 Sofia, Bulgaria
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Faculty of Geology and Geography, Department of Mineralogy, Petrology and Economic Geology, Sofia University “St. Kliment Ohridski”, 15 Tsar Osvoboditel Blvd., 1504 Sofia, Bulgaria
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Geological Institute, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl. 24, 1113 Sofia, Bulgaria
Earth and Man National Museum, 4 Cherni Vrah Blvd., 1421 Sofia, Bulgaria
Faculty of Geology and Geography, Department of Mineralogy, Petrology and Economic Geology, Sofia University “St. Kliment Ohridski”, 15 Tsar Osvoboditel Blvd., 1504 Sofia, Bulgaria
Geological Institute, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl. 24, 1113 Sofia, Bulgaria
Abstract:
Molybdenite is the main important carrier of Re. There are some hypotheses that the 3R molybdenite polytype could carry more Re in its structure. This study aims to provide initial data for different polytypes of molybdenite from the Panicherevo molybdenum deposit. There is a negative correlation between polytype formation and chemical content. Samples were characterized by means of powder X-ray diffraction and Raman spectrometry in order to reveal the presence of 2H1 and 3R molybdenite polytypes. LA-ICP-MS analyses reveal that, in the 2H1 polytype, trace elements are more abundant than in the 3R polytype.
Department of Environmental Sciences, Basel University, 4056 Basel, Switzerland
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Faculty of Geology and Geography, St. Kliment Ohridski University, 1000 Sofia, Bulgaria
Department of Environmental Sciences, Basel University, 4056 Basel, Switzerland
Faculty of Geology and Geography, St. Kliment Ohridski University, 1000 Sofia, Bulgaria
Abstract:
The Rhodope Massif represents a large high-grade metamorphic complex situated in the Balkan Peninsula, straddling the border between Bulgaria and Greece. Geological studies carried out during the last thirty years clearly established that the complex is composed of three major lithotectonic units characterized by differing protolith ages and Alpine thermotectonic evolution. The Rhodope Massif consists of Upper and Lower terranes representing continental fragments composed mainly of pre-Mesozoic magmatic rocks and covered by Early Mesozoic sedimentary sequences. These two entities are separated by an Intermediate Terrane comprising a Jurassic magmatic arc and its host rocks tectonically intercalated with Jurassic ophiolitic fragments together with the Early Mesozoic sediments.
Detailed analyses of the previously published geochronological data revealed that the three main tectonic terranes were juxtaposed in the Late Jurassic–Early Cretaceous during the continental collision and northward subduction of the Lower and Intermediate terranes. These rocks experienced Middle Jurassic to Early Cretaceous high-pressure metamorphism, followed by high-temperature one accompanied by anatexis. At that time, the Upper Terrane was metamorphosed and deformed only partially. Being part of the European margin, this terrane represented an upper continental plate during the subduction, and therefore is not considered as a part of the Alpine Rhodope metamorphic complex.
It is important to note that, although most of the present-day fabric and major tectonic zones in the Rhodope metamorphic complex are younger than Early Cretaceous, and therefore they postdate the geological evolution discussed in this study, they often reactivate the old boundaries between the main terranes and units.
Climate, Atmosphere and Water Research Institute, Bulgarian Academy of Sciences, 66 Tsarigradsko Shose Blvd, 1784 Sofia, Bulgaria
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Geological Institute, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl. 24, 1113 Sofia, Bulgaria
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Geological Institute, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl. 24, 1113 Sofia, Bulgaria
Climate, Atmosphere and Water Research Institute, Bulgarian Academy of Sciences, 66 Tsarigradsko Shose Blvd, 1784 Sofia, Bulgaria
Geological Institute, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl. 24, 1113 Sofia, Bulgaria
Geological Institute, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl. 24, 1113 Sofia, Bulgaria
Abstract:
Groundwater is an important component of river runoff, the quantification of which provides valuable information for water management. This study aims to evaluate the spatial and temporal variations in the contribution of groundwater to the river flow in the Mesta River Basin. Two tasks were performed with corresponding research methods and study periods. The first one aimed to determine the spatial distribution of the groundwater runoff modulus values (Mgw) by processing mean monthly flow data from numerous headwater stations for the period before the strong anthropogenic impact on the river system. The map of the groundwater runoff modulus was created based on the positive association of the Mgw values with the mean elevation of the catchments and the associated regression equation. Focusing on temporal analysis, for the second task, two-pass digital filtering was applied in order to separate groundwater from the daily time series of river runoff, which allows distinguishing the quick part of baseflow from the total groundwater runoff. The results from the application of this method showed the temporal distribution of groundwater runoff, which occurs mainly in spring, thus indicating a marked seasonality of this phenomenon. The proportion of groundwater flow in the formation of the river flow of the Mesta River Basin at Momina Kula was assessed as 26–27%. The results of the study are expected to better support water management decisions.
National Museum of Natural History, Bulgarian Academy of Sciences, 1 Tsar Osvoboditel Blvd, 1000 Sofia, Bulgaria
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National Museum of Natural History, Bulgarian Academy of Sciences, 1 Tsar Osvoboditel Blvd, 1000 Sofia, Bulgaria
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Plovdiv University “Paisiy Hilendarski”, Faculty of Biology, Department of Ecology and Environmental Conservation, 24 Tsar Asen Str., 4000 Plovdiv, Bulgaria
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National Museum of Natural History, Bulgarian Academy of Sciences, 1 Tsar Osvoboditel Blvd, 1000 Sofia, Bulgaria
National Museum of Natural History, Bulgarian Academy of Sciences, 1 Tsar Osvoboditel Blvd, 1000 Sofia, Bulgaria
National Museum of Natural History, Bulgarian Academy of Sciences, 1 Tsar Osvoboditel Blvd, 1000 Sofia, Bulgaria
Plovdiv University “Paisiy Hilendarski”, Faculty of Biology, Department of Ecology and Environmental Conservation, 24 Tsar Asen Str., 4000 Plovdiv, Bulgaria
National Museum of Natural History, Bulgarian Academy of Sciences, 1 Tsar Osvoboditel Blvd, 1000 Sofia, Bulgaria
Abstract:
The studied fossil material of birds and mammals from a new Late Pleistocene site in the Stara Planina (Balkan) mountain range is herein presented. The age of the site was determined on the basis of the taxonomic composition of the mammal fauna. A total of 28 taxa (10 birds, 15 small and 3 large mammals) have been identified from 103 bone/teeth specimens. Of these, 14.3% of the established species are extinct/disappeared – Perdix palaeoperdix, Megaloceros giganteus, Ursus ingressus and Cuon sp. Most numerous are the remains of Microtus arvalis-agrestis, representing 42.7% of all finds.
MOST POPULAR
Vol. 21 (5)/October 1991 - p. 99
Dimitar Kozhoukharov
Geological Institute, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria
Vol. 39 (1-2)/September 2010 - pp. 31-32
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Stela Atanasova-Vladimirova
Bulgarian Academy of Sciences, Institute of Physical Chemistry, Bulgaria
Albrecht von Quadt
Institute of Isotope Geochemistry and Mineral Resources, ETH Zurich, Switzerland
Peter Marchev
Bulgarian Academy of Sciences, Geological Institute, Bulgaria
Irena Peytcheva
Institute of Isotope Geochemistry and Mineral Resources, ETH Zurich, Switzerland; Bulgarian Academy of Sciences, Geological Institute, Bulgaria
Iskra Piroeva
Bulgarian Academy of Sciences, Central laboratory of Mineralogy and Crystallography, Bulgaria
Bozhidar Mavrudchiev
Sofia University, Department of Mineralogy, Petrology, Ores and Minerals, Bulgaria
Vol. 39 (1-2)/September 2010 - pp. 404-405
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Sorin Silviu Udubasa
Department of Mineralogy, Faculty of Geology and Geophysics, University of Bucharest, 010041, Bucharest, Romania
Gheorghe Udubasa
Department of Mineralogy, Faculty of Geology and Geophysics, University of Bucharest, 010041, Bucharest, Romania
CONTACT DETAILS
GEOLOGICAL INSTITUTE “Strashimir Dimitrov”
Acad. G. Bonchev Str., Bl. 24
1113 Sofia
Bulgaria
Phone: +359 (02) 979 2250
Fax: +359 (02) 8724 638
E-mail: editorial-office@geologica-balcanica.eu
PUBLISHER
BULGARIAN ACADEMY OF SCIENCES
GEOLOGICAL INSTITUTE “STRASHIMIR DIMITROV”
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